The traditional approach to a course of orthodontic treatment in a patient whose teeth require repositioning has been to achieve the necessary movement of the teeth by the application of orthodontic appliances generally known as braces. These orthodontic appliances are typically formed of a series of metal bands which encircle the teeth and are interconnected by wires which can be selectively adjusted as required to cause the teeth to assume the most orthodontically desirable positions. Such positions can also be achieved by the application of bonded brackets or removable devices well known to those skilled in the orthodontic art. These positions are determined with respect to such considerations as proper occlusion and aesthetic appearance. Once the teeth are correctly positioned, a period of time is required during which the teeth must be maintained in their correct positions to stabilize them and allow them to reach a state of equilibrium with the forces exerted on the teeth by the tongue, the perioral and intraoral muscles, recalcification of the bone and reorganization of the many fibers between tooth and bone and between tooth and tooth. In addition, the settling of the teeth into proper occlusal relationships influences the time required to reach the required equilibrium. This time period can vary considerably, depending upon whether the repair of bone, periodontal structures or gingival attachments had to be achieved to produce the desired tooth movement. The stabilizing function is typically performed by the application of a second orthodontic appliance known as a retainer. Previously, the sequential application of these two separate orthodontic appliances has been required to provide a complete course of orthodontic treatment for most orthodontic patients.
The available retainer-like orthodontic appliances are intended to be employed solely for retaining the teeth in previously achieved orthodontically correct positions. A retainer-like orthodontic appliance has not heretofore been disclosed which can perform both the conventional retention function just described and the repositioning functions normally performed by other orthodontic appliances. In addition, the known orthodontic retainers are characterized by certain disadvantages which interfere with the optimum performance of their retention function. For example, a commonly employed design of orthodontic retainer includes a hard plastic overlay molded to conform to the contours of the patient's hard palate and fit securely against the lingual surfaces of the teeth which supports a single strand of wire extending horizontally across the labial surface of the anterior teeth. The retainer wire must be fitted to each individual patient and usually extends from the interproximal of the cuspid and first bicuspid to the interproximal of the opposite cuspid and first bicuspid, although the wire may extend around all of the teeth. The tension of the wire and, thus, the pressure exerted by the wire to maintain the teeth in their correct positions is adjusted by varying the distance between the vertical legs of a pair of opposed, inverted U-shaped adjustment loops. A retainer wire of this design is difficult to adjust so that the optimum amount of pressure is applied to the teeth. Another type of available retainer which is also difficult to adjust provides a wire with plastic poured over it so that it conforms exactly to the teeth to be retained.
The orthodontic retainer disclosed in U.S. Pat. No. 3,994,068 to Robert A. Goshgarian includes an improved adjustment loop configuration which reduces the retainer wire adjustment problem to a great extent. However, as is the case with other prior art retainers, the function of this retainer is limited to maintaining the teeth in the optimum positions achieved by the prior application of other orthodontic appliances. Neither the retainer disclosed in U.S. Pat. No. 3,994,068 nor other known prior art retainers is capable of performing both the positioning functions typically performed by other orthodontic appliances and the retention functions performed by conventional retainers.